A radar is a device which determines information such as a distance, a speed, or an angle of a target. That is, the radar radiates an electromagnetic wave signal through a transmission antenna to receive a signal which is reflected and returns from the target through a reception antenna and uses the received signal to determine information on the target.
The radar technique was developed from a military and aviation field and recently applied to a vehicle as a technique which gives a warning in advance and actively prevents and avoids dangerous car accidents.
However, in vehicle radar environments, it is difficult to determine information on multiple targets in continuous cluttered environments such as a tunnel, a guard rail, or a building. In such cluttered environments, generally, an order statistics constant false alarm rate (OS-CFAR) detector is efficiently used to detect multiple targets. However, the OS-CFAR detector causes excessive operating time due to a sorting process.
Korean Patent No. 1,109,150 discloses a constant false alarm rate detecting method. Even though the detecting method is aimed at improving a computation amount, the detecting method basically follows an order statistic method so that it is difficult to achieve a rapid improvement of an operating speed.